The PL84 audio output pentode was designed for use in television receivers.

110° deflection picture tubes required considerable power to the deflection coils and the PL84 was designed for frame output service as well as audio.

The PL84 is based on the EL84 audio output valve but designed for lower HT voltages.

The carbonised anode is formed from two thin strips of nickel stitched together. The PL84 is a true pentode with a wire suppressor grid.

The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 70 mm tall.

References: Datasheet & ¹⁰⁴⁰. Type PL84 was first introduced^¶ in 1956.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	ic	g1	k	h	h	ic	a	ic	g2

 
Absolute Maximum Operating Conditions^¶

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm	Pout	D
	15	0.3	170	170	-12.5	70	5.0	20,000	6.4	3.5W	10%

Thanks to Frank Philipse for supplying the above PDF datasheet

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